The present disclosure relates to a mixing chamber for mixing exhaust gas with intake air in an engine. The mixing chamber has an intake air inlet, an exhaust gas inlet and a mixing post. The mixing post is located downstream of the charge air inlet and upstream of a point where the flow of exhaust gas meets the flow of intake air, the mixing post extending across the mixing chamber. The mixing post has a longitudinal axis which is oriented perpendicular to a longitudinal axis of the mixing chamber.